Gareth Huxham
BE (Mechatronic),
PhD Research Student
Environmental Fluids Group
School of Civil Engineering, Room 101
Phone: 0402 435 653
Fax: +61 2 9351 3343
Email: ghux5691@usyd.edu.au
Research project - Energy extraction from laminar and turbulent flows by biomimetic hydrofoil
Supervisor: Dr Tim Finnigan
Associate Supervisor: Dr. Stefan Williams (Australian Centre of Field Robotics)
Through the process of natural selection fish have developed highly efficient modes of underwater locomotion designed to enable high speeds, efficient long distance swimming and advanced manoeuvrability.
A significant body of research has been conducted on understanding fish locomotion and applying the principles to biomimetic foils. The majority of research has focused on using biomimetic foils to generate efficient thrust / propulsion and improve the manoeuvrability of underwater vehicles.
The aim of this research doctorate is to investigate the extraction of useful energy from a flow. Here the ‘fish body’ is fixed and the ‘fish tail’ is forced to ‘swim’ by controlling the angle of attack of the ‘caudal fin’ to the flow. The lift and drag forces that are generated drive the movement of the tail. A possible future application of this research is developing a device to extract renewable energy from tidal currents. For example the ‘fish tail’ can drive a turbine or pump hydraulic fluid through a turbine.
The image below shows a schematic of the proposed device.
Device: Oscillating hydrofoil on a hinged lever arm
What is biomimetic?
By biomimetic we mean an engineered device inspired by the biological world around us, designed using principles observed directly from nature. Inspiration may come from a range of sources including fish, plants, single cell organisms or an entire eco system.
Here, the device we are developing is designed to model several aspects of the highly efficient thunniform swimming mode which is used by several fish species including tuna and great white sharks. Thunniform swimming is characterised by a relatively stiff fish body and a large lateral motion of a high aspect ratio caudal fin. Our device models the caudal fin with a NACA foil and the fish tail by a hinged lever arm.
Adaptive control in turbulent flows
Research has shown that several fish species have the capability to alter their swimming dynamics in response to changes in the oncoming flow to improve the swimming efficiency. Studies of rainbow trout swimming in the Karman Street generated in the wake of a D shaped cylinder indicate they are able to tune their body movements to changes in the flow, synchronising with the shed vortices. This enables the trout to maintain a set speed with a lower exertion.
One of the objectives of this research doctorate is to investigate whether the device can learn to operate in different flows: to characterise the flow, detect large events in the flow and respond accordingly to maximise energy extraction.
Learning and Teaching Duties
- CIVL2611 Fluid Mechanics